<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>标签选择器</title>
    <style type="text/css">
        /* 标签选择器 */
        H1 {
            color: red;
        }
        h2 {
            color: green;
        }
        P {
            color: pink;
        }
    </style>
</head>
<body>
    <!--  -->
    <h1>一级标题</h1>
    <div>
        <h1>一级标题</h1>
    </div>
    <h2>这是 heading 2</h2>
    <p>这是一段普通的段落。</p>
</body>
</html>